1. ## Linear Approximation

I'm faced with this problem which I currently do not know how to solve because of all of the variables in the formula I am supposed to generate: Could anyone shed some light on this?

2. This looks like part of a graded assessment. It is forum policy not knowingly to help with such problems.

3. They are online practice problems, my main concern is the radius part where it says a changes from a to a+dr is this the same as a changing to $\Delta r$ as in the d signifying a small change because then that would make sence

4. Problem solved: $\Delta V \approx 4\pi a^2dr$

and $\Delta V \approx 2560\pi cm^3$